1. Field of the Invention
Embodiments of the present invention generally relate to forming an amorphous silicon film. More particularly, embodiments of the present invention relate to forming an amorphous silicon film utilized in display devices.
2. Description of the Related Art
Display devices have been widely used for a wide range of electronic applications, such as mobile phone, mp3 players, e-book, and personal digital assistants (PDAs) and the like. The display device is generally designed for obtaining desired image signals by applying an electric field to a liquid crystal that fills a gap between two substrates and has anisotropic dielectric constant that controls the intensity of the dielectric field. By adjusting the amount of light transited through the substrates, the light and image intensity, quality and power consumption may be efficiently controlled.
Recently, touch screen panels (TSP) have become widely used as input means that reads the coordinates of the point touched by the user. A variety of different display devices, such as active matrix liquid crystal display (AMLCD) or an active matrix organic light emitting diodes (AMOLED), may be employed as light sources of display device which have touch screen panels attached and integrated thereto. The display devices employ photosensitive elements, such as an silicon based NIP photodiode. The photosensitive element is coupled to a readout switch, such as thin film transistor (TFT), that provides data indicative of received light. As thin film transistor (TFT) are utilized in active matrix liquid crystal displays (AMLCD) or active matrix organic light emitting diodes (AMOLED), each thin film transistor (TFT) functions as a switch for a pixel in a matrix display. NIP diodes and thin film transistor (TFT) utilize a-Si, polycrystalline silicon or other silicon-containing films as a semiconductor material. However, current practice for integrating of the touch screen panels (TSP) to NIP photo diodes and thin film transistors (TFTs) in liquid crystal displays (LCD) or organic light emitting diodes (OLEDs) suffers high manufacture cost, poor reliability, low display transmittance, and limited service life.
Therefore, there is a need for an improved integrated touch screen technology that provides high optical performance, long device lifetime, and low manufacturing cost.